Adaptable cab floor engagement assembly for commuter and conventional jet aircraft

ABSTRACT

An engagement structure adapted for securement to the end of an aircraft boarding bridge includes a floor, a first floor panel rotatably associated with the floor, and a second floor panel displaceably associated with the floor. The second floor panel is preferably mechanically associated with a drive assembly adapted for displacing the second floor panel relative to the first floor panel to provide a dimensionally adjustable floor area of a boarding bridge proximate the interface of the bridge and an aircraft serviced by the bridge. The engagement structure is adapted to accommodate the docking of the boarding bridge with aircraft having varied entry door configurations.

CROSS-REFERENCE TO RELATED APPLICATION

Pursuant to the provisions of 35 U.S.C. 119(e), this application claimsthe benefit of the filing date of provisional patent application Ser.No. 60/238,169, filed 5 Oct. 2000, for “Adaptable Cab Floor EngagementAssembly For Commuter and Conventional Jet Aircraft,” which isincorporated herein by reference. Further this application is adivisional application of U.S. application Ser. No. 09/971,975 for“Adaptable Cab Floor Engagement Assembly For Commuter and ConventionalJet Aircraft” filed 4 Oct. 2001 now U.S. Pat. No. 6,898,816, which isalso incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field

This invention relates to apparatus for use in servicing aircraft atairports. More specifically, the invention is directed to aircraftboarding bridges which are adapted for permitting egress from andingress to an aircraft positioned adjacent to an airport terminalbuilding.

2. Statement of the Art

Aircraft boarding bridges have become a commonplace phenomena at airportterminals both in this country and abroad. Such bridges provide apassageway for aircraft passengers and crew from the terminal buildingto an aircraft parked proximate to the terminal building. These bridgesare highly valued for their ability to shelter aircraft passengers andcrew from inclement weather as well as their ability to facilitateaccess to the aircraft for those having special needs, such as thedisabled.

A reoccurring requirement encountered at airports is the need to provideboarding bridge access to a multiplicity of aircraft types. Given theexistence of a number of aircraft manufacturers, each with their ownparticular aircraft doorway design and the lack of a standardizedconfiguration for the entryway of an aircraft, airport service personnelare confronted on a daily basis with the need to provide an access wayto a number of aircraft doorway configurations and orientations with asingle boarding bridge assembly.

A primary example of this circumstance are the requirements posed by thedoor configurations typically found on large commercial aircraft versesthe door configurations found on smaller commuter-type aircraft. In thecase of the large commercial aircraft, the door is opened by means of alateral displacement of the door panel, e.g., the door may open bypivoting about a vertical axis. Traditional boarding bridgeconstructions permit the bridge to be docked against the aircraftfuselage subsequent to the opening of the aircraft door. The manycommercial aircraft the door is pivoted about its vertical axis. Sincethe path of travel of the door is above the floor of the boardingbridge, the positioning of the boarding bridge floor against thesidewall of the aircraft does not impede the opening or closing of theaircraft door. Since the aircraft door does not come into contact withthe floor structure of the boarding bridge during either the opening orclosing procedure, boarding bridges have typically been constructed todefine a planar floor element which is positioned elevationally belowthe door opening and positioned to extend outwardly from the doorway ofthe aircraft when the bridge is in a docked position.

In contrast, commuter aircraft oftentimes utilize a door assembly whichpivots about a horizontal axis, positioned at the lower end of the door.In many instances, the door of a conventional commuter aircraft isfitted with a series of steps on its interior surface. Furthermore, thedoor assembly is oftentimes fitted with a handrail assembly whichextends upwardly from the opposing sides of the door when the door islowered into an open position.

In its open position the door defines a stairwell for accessing theaircraft or alternatively deplaning from the aircraft. The fact thatcommuter aircraft doors pivot about a horizontal axis creates a numberof complications for the operator of a conventional boarding bridgestructure which has been designed for use with aircraft having doorswhich pivot about a vertical axis. In those instances wherein a bridgeis used to service a commuter aircraft, the bridge is conventionallybrought into abutment against the aircraft fuselage subsequent to theopening of the aircraft door. The operator of a conventionallyconstructed bridge is confronted with the problem of accommodating theboarding bridge to a door having upstanding structure which is not aconventional feature of doors found on commercial aircraft. Of specificconcern is the provision of a floor arrangement which provides a safeegress and ingress from the aircraft portal to the main structure of theboarding bridge.

It should be appreciated that aircraft boarding bridges seek to providea passageway which is of considerable height above the surface of theunderlying tarmac. Understandably, considerations of safety play apivotal role in boarding bridge design. Changes in the configuration ofthe floor system of a boarding bridge, which are often mandated intransitioning from servicing an aircraft of one type to servicing anaircraft of a different configuration, present a significant safetyconcern in that adequate measures need to be taken to precludepassengers from inadvertently falling through openings in the floorsystem which may be created during any reconfiguration of the floorsystem.

It follows that there presently exists a need for an engagementstructure for a boarding bridge which at once addresses the need toprovide a means of accommodating varied aircraft door constructions,particularly vertically pivoted doors and horizontally pivoted doors.Some effort has been made in the past to address this issue. One sucheffort is disclosed in U.S. Pat. No. 6,122,789 (Stephenson et al).

Notwithstanding the efforts made in the past, a continuing need existsfor an engagement structure adapted for providing a dimensionallyadjustable floor system for the transition area between the aircraft andthe main structure of the boarding bridge which likewise is suitable foruse with both types of aircraft door structures. It is furtherrecognized that such an engagement structure should minimize safetyconcerns. Such an engagement structure should provide flexibility andadaptability whereby the boarding bridge may be used to service aircrafthaving a variety of doorway constructions of various dimension,configuration, orientation and operation.

BRIEF SUMMARY OF THE INVENTION

An adaptable cab floor adapted for use with an aircraft boarding bridgeis disclosed. The cab floor includes a frame structure which supports agenerally horizontal floor surface. In a first orientation the framestructure and floor surface define an opening dimensioned to permit thepassage there through of a door, or a portion of a door, of a commuteraircraft, e.g., a door which rotates about a horizontal axis. The framestructure is fitted with an assembly adapted to provide a walkingsurface over the aforesaid opening in a second orientation. Thisassembly includes at least one floor panel which is displaceablerelative to the frame structure. The frame is fitted with a first floorpanel which is rotatably connected to the frame structure about itsproximal end. The first floor panel defines an upper surface configuredto provide a walking surface for passengers exiting or entering theaircraft. This first floor panel extends outwardly from the framestructure and is oriented, in a first condition, to extend from itsproximal end positioned adjacent to the frame structure to its distalend which is positioned proximate the door portal of an aircraftpositioned adjacent to the cab floor assembly. In this first condition,the first floor panel extends into or over the aforesaid opening todefine a bridge between the floor surface of the frame structure and theentry/exit portal of the aircraft. In a second condition, the firstfloor panel is rotated out of the opening defined by the floor structuresufficiently to permit the passage through the opening of the door andassociated airstair assembly of a commuter aircraft.

The first floor panel defines two opposing longitudinal edges. In apreferred embodiment, the first floor panel is associated with one ormore supplemental side panels. Each of these side panels may beconnected to the first floor panel proximate a respective longitudinaledge of the first floor panel. Alternatively each of the side panels maybe connected to the frame whereby the side panels are displaceable to anorientation wherein they provide a floor surface between the frame andthe longitudinal edges of the first floor panel. In this latterconstruction, each of the side panels may be disposed for rotation abouta horizontal axis which is mounted parallel to its respective firstfloor panel longitudinal edge.

In one embodiment of the invention a second floor panel is mechanicallyconnected to the first floor panel. The second floor panel defines anupper surface configured to form a walking surface for passengersexiting or entering the aircraft. The second floor panel is constructedto be displaceable, either manually or by means of a driving structure,outwardly from the first floor panel to form a walkway from the aircraftportal to the first floor panel and thereafter to the boarding bridgestructure. The second floor panel is therefore displaceable between afirst condition, wherein the second floor panel is generally nested in,below or above the first floor panel and a second condition wherein thesecond floor panel is displaced outwardly from the first floor panel toform an extension of the floor surface formed by the first floor panel.When the second floor panel is positioned in the first or retractedcondition, and the first floor panel is in a first condition, aslot-like void or recess is defined between the proximal edge of thesecond floor panel and the forward most portion of the floor surface ofthe frame structure. This slot-like void is of sufficient dimension toreceive the upstanding sections of an opened door of a commuteraircraft. Once the engagement assembly is docked to the aircraft, thesecond floor panel is displaced to its second condition whereby theproximal end of the second floor panel is positioned into the openportal of the docked aircraft thereby forming a bridge or passageway tothe main structure of the boarding bridge. The first floor panel, beingpivotally secured to the frame of the boarding bridge cab, may rotateabout its axis of rotation in the event that the first or second floorpanels is brought into contact with any underlying structure such asportions of the opened aircraft door. This rotational capacity permitsthe first and second floor panels to rotate about their joint axis ofrotation whereby the door panels are displaced thereby limiting oravoiding damage to either the boarding bridge or the opened aircraftdoor.

In a second embodiment, the second floor panel may be rotatablyconnected to the frame structure to rotate about a first end thereof.Similar to the second floor panel, this alternative second floor panelmay define an upper surface configured to define a walking surface forpassengers exiting or entering an aircraft. The side edge of thisalternative second floor panel, in an extended orientation, ispositionable adjacent to the portal of an aircraft parked adjacent tothe cab floor assembly. In this extended orientation, the upper surfaceof the alternative second floor panel intercooperates with the floorsurface of the first panel to form a walking surface which covers theaforesaid opening or slot. In a retracted orientation of the alternativesecond floor panel, a slot-like void or recess is defined between alongitudinal edge of the first floor panel and a perimeter of the framestructure. In contrast to the first embodiment, the alternative secondfloor panel is not mounted within or below the first floor panel.Instead, the alternative second floor panel is positioned adjacent tothe first floor panel and in some constructions may actually bepositioned to overlap a portion of the first floor panel.

The alternative second floor panel may be rotated by a respectivedriving structure or alternatively may be manually operated. Thealternative second floor panel is rotatable independent of the firstfloor panel to permit the cab floor assembly operator to vary theconfiguration of the cab floor and thereby adapt the cab floor to theparticular construction of the aircraft portal structure being presentlyserviced by the boarding bridge.

A third floor panel may also be rotatably connected to the framestructure to rotate about a proximal end thereof. Similar to the secondfloor panel, this third floor panel may define an upper surfaceconfigured to define a walking surface for passengers exiting orentering an aircraft positioned adjacent to the engagement assembly. Theproximal end of the third floor panel, in an extended orientation, ispositionable adjacent to the portal of an aircraft positioned adjacentto the cab floor assembly. In this extended orientation, the uppersurface of the third panel intercooperates with the floor surface of thefirst panel and the upper surface of the second panel to form a walkingsurface which covers the aforesaid opening. In a retracted orientationof the third floor panel, a slot-like void or recess is defined betweena longitudinal edge of the first floor panel and a second edge of theframe structure. This slot-like void or recess is of sufficientdimension to permit the passage therethrough of a second hand railassembly of a commuter aircraft door assembly. In some embodiments, thethird floor panel may be positioned contiguous to the upstanding wall ofthe cab assembly. In this latter instance, the second edge of the frameassembly is defined by the upstanding wall as opposed to the floorsurface of the frame structure.

In those embodiments which include side panels interconnected to thefirst floor panel, these side panels may be adapted to be positionablein a somewhat upstanding orientation to form a vertical restraint orguard for the floor surface formed by the first floor panel. In thisgenerally upstanding orientation, these side panels may be positionedproximate or in abutment with the hand rail assemblies of the commuteraircraft door to form an upstanding barrier along the edge of the floorsurface defined by the first floor surface. When the first floor panelis in a first condition and the second and third floor panels are inextended orientations, the side panels are positionable to extendbetween the longitudinal edges of the first floor panel and the uppersurface of a respective second or third floor panel to thereby form agenerally planar walking surface which extends from an outermostlongitudinal edge of the second floor panel to the outermostlongitudinal edge of the third floor panel.

The first, second and third floor panels may be each rotated by arespective driving structure. Each of these floor panels is rotatableindependent of the other floor panels to permit the cab floor assemblyoperator to vary the configuration of the cab floor and thereby adaptthe cab floor to the particular construction of the aircraft portalstructure being presently serviced by the boarding bridge.

The opening defined by the frame structure and its associated floorsurface forms a passageway of sufficient dimension to accommodate theprotruding platform often found on commuter type aircraft which platformforms part of the deployable airstair. A displacement, e.g., rotation,of the first floor panel to a closed orientation may be adopted topartially close the aforesaid opening passageway sufficiently to providea passenger passageway from the aircraft to the main structure of theboarding bridge. These two floor panels may be displaced in variousarrangements to provide a floor structure between the boarding bridgeand the aircraft of sufficient dimension and configuration to permit thepassage of passengers there over into and out of the aircraft.

Accordingly, the cab floor assembly provides the operator with a meansof providing a dimensionally adjustable embarkation platform adjacent tothe aircraft portal and a means of adjusting the configuration of theinterface between the bridge and the fuselage of the aircraft. As may beappreciated, the cab floor assembly may be adapted to accommodate amultiplicity of aircraft door configurations, dimensions, orientationsand operational characteristics on an individualized basis.

The invention therefore provides a construction whereby the floor of theboarding bridge cab may be reconfigured to define a passagewaydimensioned to accommodate the platform of commuter type aircraft duringits opening or closing procedure. The floor may then be reconfigured todefine an embarkation platform of sufficient dimension, adjacent to theopen doorway of a conventional commercial aircraft, to provide for thepassage there over of passengers and crew entering or leaving theaircraft.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a partial elevated perspective view of a passenger boardingbridge fitted with the adaptable cab floor assembly of the instantinvention. The adaptable cab floor assembly is shown in a closedcondition;

FIG. 2 is a partial elevated view of a boarding bridge illustrating asecond floor panel of the cab floor assembly in a retracted condition;

FIG. 3 is a further elevated view of a boarding bridge illustrating thefirst and second floor panels of an adaptable cab floor assembly in aretracted condition;

FIG. 3A is an elevated partial perspective view of the adaptable cabfloor assembly with the second floor panel in a retracted condition;

FIG. 3B is an elevated partial perspective view of the cab floorassembly illustrating the second floor panel in an extended condition;

FIG. 3C is an elevated partial perspective view of the cab floorassembly taken from another perspective illustrating a partial extensionof the second floor panel;

FIG. 3D is an elevated partial perspective view of the cab floorassembly, taken from the perspective of FIG. 3C illustrating the firstand second floor panels rotated about the horizontal axis of the firstfloor panel;

FIG. 3E is a partial perspective view of the cab floor assembly takenfrom below the floor assembly illustrating the second floor panel in aretracted condition;

FIG. 3F is an elevated partial perspective view of the cab floorassembly, taken from the perspective of FIG. 3E illustrating the secondfloor panel in an extended condition;

FIG. 3G is an partial perspective view of the cab floor assembly inassociation with the deployable airstair of an aircraft;

FIG. 3H is a cross-sectional view of a engagement assembly of theinvention shown in an extended condition;

FIG. 3I is a cross-sectional view of the engagement assembly of FIG. 3Hshown in a retracted condition;

FIGS. 3J–3L are cross-sectional views of the engagement assembly of theinvention illustrating a transition free intercooperation of the firstand second floor panels;

FIG. 4 is a cross-sectional side view of an aircraft in association witha boarding bridge of the instant invention shown in a conventionalpassenger unloading orientation;

FIG. 5 is a cross-sectional side view of the aircraft and boardingbridge association of FIG. 4 wherein the relative positioning of theaircraft and the boarding bridge has shifted thereby causing a rotationof the first and second floor panel boarding bridge engagement assemblyas that assembly contacted the upstanding structure of the airstair;

FIG. 5A is a partial perspective view of the cab floor assembly in aclosed condition;

FIG. 6 is a partial elevated perspective view of a passenger boardingbridge fitted with an alternative construction of the adaptable cabfloor assembly of the instant invention. The adaptable cab floorassembly is shown in a closed condition;

FIG. 7 is a partial elevated view of a boarding bridge illustrating asecond floor panel of the cab floor assembly in a retracted condition;

FIG. 8 is a further elevated view of a boarding bridge illustrating thefirst and second floor panels of an adaptable cab floor assembly in aretracted condition;

FIG. 9A is an elevated partial perspective view of the adaptable cabfloor assembly with a cover plate shown positioned atop the boardingbridge engagement assembly;

FIG. 10 is a partial elevated perspective view of a passenger boardingbridge fitted with the adaptable cab floor assembly of the instantinvention. The adaptable cab floor assembly is shown in a retractedcondition;

FIG. 11 is a partial elevated perspective view of a cab floor assemblyof the instant invention;

FIG. 12 is a partial elevated view of a boarding bridge illustrating afirst floor panel of the cab floor assembly in an extended condition;

FIG. 13 is a further elevated view of a boarding bridge illustrating thefirst, second and third floor panels of an adaptable cab floor assemblyin an extended orientation;

FIG. 14 is an elevated partial perspective view of the adaptable cabfloor assembly with the first, second and third floor panels in aretracted condition;

FIG. 15 is an elevated partial perspective view of the cab floorassembly illustrating the first floor panel in the process of beingextended;

FIG. 16 is an elevated partial perspective view of the cab floorassembly illustrating yet a further extension of the first floor panel;

FIG. 17 is an elevated partial perspective view of the cab floorassembly illustrating the first floor panel extended to a generallyhorizontal orientation;

FIG. 18 is an elevated partial perspective view of the cab floorassembly with the side panels of the first panel being positioned inabutment against the support structure of the second and third floorpanels;

FIG. 19 is an elevated partial perspective view of the cab floorassembly illustrating the second and third floor panels being displacedto an extended orientation;

FIG. 20 is an elevated partial perspective view of the cab floorassembly illustrating a further displacement of the second and thirdfloor panels to an extended orientation;

FIG. 21 is an elevated partial perspective view of the cab floorassembly illustrating the disposition of the first, second and thirdfloor panels in an extended orientation;

FIG. 22 is an elevated perspective view of an alternative embodiment ofthe cab floor assembly;

FIG. 23 is a perspective view of the assembly in FIG. 22 with the sidepanels in an inclined orientation; and

FIG. 24 is an alternative configuration of the embodiment of FIG. 22with the side panels in an inclined orientation.

DETAILED DESCRIPTION OF THE INVENTION

As illustrated in FIG. 1, a boarding bridge 15 (shown in partial view)is fitted on its outer end with a cab 17. The cab 17 is a generallyenclosed structure having a pair of opposingly positioned upstandingsidewalls 19 surmounted by a ceiling or roof element 20 which extendsbetween the two sidewalls. The cab further includes a floor element 25.The floor element 5 extends between the two sidewalls. The cab alsodefines an entryway from the main boarding bridge structure. The cab 17defines an open portal 21 which is designed to interface with thefuselage of the aircraft to be serviced by the boarding bridge. Theportal 21 is defined by a framing structure 23 which extends upwardlyfrom the floor 25 in a generally inverted U-shaped configuration. Theportal frame 23 may be fitted with a canopy structure (not shown) whichextends from the frame to contact the fuselage of the aircraft. Aconventional accordion-like canopy is anticipated for this purpose.

The floor 25 is formed of two identifiable sections. The main body ofthe floor, herein designated as floor section 25A extends generallybetween the two upstanding sidewalls 19. A second section of the floor,designated as floor section 25B extends from the linear intersection ofthe two sections along the line 25C. The two sections 25A and 25B areinterconnected to one another along the line 25C of their intersectionto form a hinge-like connection. This hinged connection permits the twofloor sections to move independent of one another to accommodate touneven orientations of the two floor sections. The leading edge 30 offloor section 25A may be fitted with a bumper structure 27 as shown inFIG. 1. The leading edge 30 is configured to be positionable adjacentthe fuselage of an aircraft to be serviced by the cab floor assembly.

The edge 30 of the forward floor section 25A defines a slot or recessopening 26 in the floor 25. This slot 26 is generally defined by theleading edge 30 of the floor section 25A, the edge 28 of the floorsection 25A, the edge 29 of floor section 25A and the cab sidewallsection 31. In the illustrated embodiment, this slot 26 is illustratedas a quadrilaterally configured void adjacent to the floor structure 25.It should be understood that this slot 26 may be of any number ofdifferent configurations and shapes and furthermore may be positioned atany number of locations in the floor structure proximate the leadingedge 30 of the floor structure. In the instant illustration the slot isshown on the right side of the cab (as viewed from the docked aircraft).The slot 26 may also be on the left side of the cab, in the middleregion of the cab or any other location along the leading edge 30 of thefloor 25.

The instant invention provides a multi-segmented engagement assembly 33which may be introduced into the aforesaid slot 26 in variousconfigurations to form an embarkation platform over the slot 26 from anaircraft positioned adjacent to that slot 26. In those instances whereinthe cab floor is directed to service a commuter type aircraft having adoor assembly which rotates about a horizontal axis the boarding bridgemay be brought into position with the slot 26 in an open configurationi.e., generally devoid of structure thereby permitting the passage therethrough of the door and associated airstair assembly of a commuteraircraft positioned adjacent to the cab floor 25. Subsequent to dockingthe engagement assembly may then be reconfigured to provide the desiredembarcation platform from the portal of the aircraft to the boardingbridge structure. The slot 26 is specifically dimensioned to receive andpermit the passage there through of the upstanding portions of anairstair structure of a commuter aircraft.

During the docking procedure with a commuter aircraft, the assembly 33is held in a retracted position until the door of the aircraft has beencompletely opened and secured in its open orientation. This retractedcondition is shown to advantage in FIG. 2. Depending on the particularhand rail arrangement of the airstair, a segment of the assembly 33 maythen be displaced into the slot 26 to interface with the aircraft doorassembly and form an embarkation platform which accommodates theparticular hand rail arrangement. For example as shown in FIG. 1, theassembly 33 is illustrated configured in an arrangement which provides acentrally positioned walking surface 32.

The assembly may be fitted on its outer edge with a bumper structure 30Awhich corresponds in construction and configuration with the bumper 30which is fitted on the edge 30 of floor 25A.

The assembly 33 is pivotally secured to the floor assembly 25 along itsdistal end 35 for rotation about a horizontal axis 36 as shown in FIG.3. This pivoted mounting permits the assembly 33 to rotate upwardly inthe event that the assembly should be forcedly brought into contact withany underlying structure such as the handrail assembly of an airstair.It has been found in practice that the relative positioning of anaircraft and its associated boarding bridge may change during the timethat the aircraft is docked to the boarding bridge. This is especiallytrue during the loading and unloading of the aircraft as the weightbeing carried by the aircraft changes due to loading or unloading. Thischange in weight carried by the aircraft may cause the elevation of theaircraft to be either increased or decreased depending on the amount ofweight change. In the event that the elevation of the aircraftincreases, i.e., the aircraft rises, the assembly 33 may be brought intoa forced contact with the airstair structure as that airstair structurerises with the aircraft. The pivoted mounting of the assembly 33 permitsthe assembly to rotate upwardly thereby minimizing the force of thecontact between the assembly and the rising airstair. The rotationtherefore avoids or minimizes any damage to either the airstair or theassembly 33. A rotation of the assembly 33 is shown to advantage in FIG.3.

FIGS. 3A–3L illustrate the multi-segmented assembly 33 in the context ofthe cab floor assembly. As shown, the cab floor 25 includes a framestructure 41 formed of a number of elongate frame members 43 which arepositioned in spaced, relationship to one another. The frame members 43are interconnected to one another by cross members 45 which are spacedlypositioned from one another. The frame members 43 and 45 are connectedto one another at their various intersections or junctures to form aframe structure having an upper surface suited for receiving andretaining the floor panel 25. The panel, which forms the floor element25, is connected to the frame structure to define a walking surface.

Positioned within the slot 26 defined by the floor 25 is the engagementassembly 33. This assembly 33 includes principally two floor panels, afirst floor panel structure 37 and a second floor panel structure 39. Asshown first floor panel structure 37 includes a generally planar walkingsurface panel 40 having a generally rectangular configuration inassociation with an underlying frame structure 38 which supports thewalking surface panel 40. The longitudinal axis 42 of the panelstructure 37 is oriented generally parallel to the leading edge 30 ofthe floor 25. The first floor panel 37 is pivotally mounted to the floor25 by pivot mounting 43 utilizing a conventional pivot mountingstructure such as a pivot axle rotatably mounted in a bracket. The pivotmounting of the first floor panel 37 permits the first floor panel 37 torotate about the rotational axis 36. The frame 41 defines two elongaterails 46 which extend along the opposing edges 47 of the slot 26. Eachof these rails defines a ledge upon which the first floor panel 37 restswhen that panel is positioned in its first, closed condition as shown inFIG. 3A. The rails 46 preclude the panel 37 from rotating below theplane of the floor 25. The rails 46 therefor form a support for thefirst panel 37.

In a preferred construction the first floor panel structure 37 mayinclude a pair of outwardly extending elements 49. These fork ortine-like elements are shown to advantage in FIG. 3. Each of theseelements 49 are generally elongate in configuration and define aslot-like opening which extends along the length of each element to forma channel 51. In this construction the free end of each element 49 isfitted with a bumper structure 30C which corresponds in construction andmaterial to the bumper 30 discussed above.

The second floor panel structure 39 defines a generally planar uppersurface 52 which forms a walking surface for passengers exiting theaircraft. The second panel structure 39 has a longitudinal dimensionwhich corresponds generally with the length of the first panel structure37. The second panel structure 39 may be configured in variousconstructions. In a first construction, the second panel structure 39may be generally planar in construction and be positioned with its sideedges disposed within the channel 51 defined within the elements 49 tobe slidable therein between a retracted condition wherein the panelstructure 39 is largely positioned beneath or within the first panelstructure 37 in a stored condition and a second extended condition,shown in FIG. 3B wherein the panel has been displaced outwardly from thefirst panel along the channels 51 so as to abut against the fuselage ofthe aircraft being serviced. The underlying frame 38 of the first panelstructure is adapted in those constructions wherein the second panelstructure is nested or stored within the body of the first panelstructure. In this latter embodiment, the frame 38 is adapted to includea pair of opposingly positioned channel defining structures mountedwithin the frame 38. Each channel defining structure defines a channelwhich interconnects with the channel 51 of a respective element 49 toform an extension of that channel within the body of the frame 38.

This orientation of the second panel structure 39 is shown in greaterdetail in FIGS. 3H through 3L. As shown therein, the second panelstructure 39 includes a planar surface panel 55 which is secured to anunderlying frame 57. The frame 57 includes a roller member 59 on each ofthe sides of the frame. Alternatively, a single roller which extendsover the complete width of the panel structure 39 may be used. Theroller or rollers are preferably rotatably mounted to the panelstructure 39. Each roller member 59 is positioned with its longitudinalaxis oriented parallel to the longitudinal axis 61 of the panel 39.

Trained about the roller 59 is a flexible band of material 60 which isdisposed over the surface 55. The first end 62 of the band 60 is fixedlysecured to the panel structure 37 at location 62. The band 60 isdimensioned to have a width which is substantially dimensionallyidentical to the width of the second panel structure 39. The opposingend of the band 60 is fitted with two cables. Each cable 63 is securedto the band 60 proximate a respective side of the band 60. Each cable 63is trained over a pulley 65 which is mounted, preferably rotatably, tothe second panel structure 39. The cable 63 is secured at its end to abracket 67 which is attached to a respective element 49. As shown inFIGS. 3H through 3L as the second floor panel is displaced between aretracted condition (FIG. 3J) and an extended condition (FIG. 3K), theband is displaced along the underside of the panel structure 39 andsubsequently around the roller 59 eventually being positioned over thesurface 55 to form a transition free walking surface for the engagementassembly. The thickness of the band 60 is dimensioned thickness-wisesuch that when the two panel structures 37 and 39 are positionedadjacent to one another and the band 60 is drawn over the surface of thesecond floor panel, the plane of the upper surface of the band 60 isgenerally co-planar with the upper surface of the upper surface of panel40 of the first panel structure. This dimensioning of the band producesa substantially planar or transition-free surface between the first andsecond panel structures 37 and 39. In this particular construction theaxle 67 of the roller 59 may be secured within the channels 51 of thetwo elements 49. In this particular construction the first panel 37 mayinclude an underlying framework structure which defines a voiddimensioned to receive and retain the second panel structure 39,including the pulleys 65, in a nested orientation when that panel is ina retracted condition.

Various power structures 70 are contemplated, including electric motorsand adjustors as well as hydraulic powered rams for displacing thesecond floor panel 39. As shown in FIGS. 3H and 3I, a hydraulic ram isshown attached to the underside of the first floor panel 37. This ram70, being mounted to the first floor panel 37 is rotatable with theassembly 33 as shown in FIG. 3L. The head of the ram 74 is shown inattached engagement with the second panel structure 39. As the ram isactuated and driven outwardly from its piston 72 the second floor panelstructure 39 is driven along the channels 51 and the band 60 slidesalong the underside of the second panel and is extended over the uppersurface of panel 55. Similarly as the ram is retracted into its cylinderthe second panel structure 39 is driven back into a nested orientationin the first panel 37.

FIGS. 4 and 5 illustrate the function of the pivoted mounting of thefirst panel structure 37 to the floor 25. FIG. 4 illustrates thepositioning of the engagement assembly during a normal unloading dockedcondition. Notably, the first and second panels 37 and 39 are shown in agenerally horizontal orientation. The engagement assembly is shown aboveand generally out of contact with the airstair 77. FIG. 5 illustrates acondition wherein the elevation of the aircraft has changed, i.e., theaircraft has been elevated by the action of its suspension system due tothe unloading of passengers, i.e., the weight of the departingpassengers has been removed from the suspension system therebypermitting that system to return the aircraft to an unloaded raised orincreased elevation. In this latter orientation, the airstair 77 iselevated together with the elevating aircraft thereby bringing theairstair into contact with the engagement assembly 33. Due to thepivoted mounting of the first panel 37, the entire engagement assembly33 is permitted to be rotated as it engages the airstair therebylessening the resistance of the engagement assembly against theairstair. The engagement structure 33 therefore rotates about the axis36 thereby lessening if not eliminating the likelihood of either theengagement assembly 33 or the airstair 77 being damaged by theircontact. In preferred constructions, the engagement assembly 33 isfitted with sensors to sense a predetermined change in the incline ofthe assembly 33. Upon the predetermined incline setting being exceededthe sensor sends a signal to a display or alternatively activates analarm to advise the operator of the orientation of the engagementassembly 33 and the need to take remedial action.

FIGS. 6–9 illustrate an alternative construction of the engagementassembly wherein the second panel structure 39 of the prior describedconstruction is replaced by a second panel structure 80 which ispivotally mounted to the floor 25 to be rotatable about a generallyhorizontal axis 81. As shown the second panel 80 is a generally planarpanel having a generally rectangular configuration. The panel ispivotally secured to the floor 25 by a pivot mounting structure 83. Thesecond panel 80 may be rotated about axis 81 to the retracted conditionshown in FIG. 8 whereby the upper surface of the panel is brought torest atop the upper surface of the floor 25 thereby exposing a portionof the slot 26. It is contemplated that the second panel 80 may beeither manually displaceable between its retracted and extendedconditions or alternatively the panel 80 may be displaced between thetwo conditions by a power driven device such as an electric or hydraulicmotor. In either case the first panel 37 is substantially similar to thefirst panel described above with the exception that elements 49 are nolonger used. In other constructions the second panel 80 may besubstantially a planar panel without an underlying support structure.

In this alternative construction of the engagement assembly, the ledges46 formed by the frame of the floor 25 function to retain the secondpanel 80 in a generally horizontal orientation when the second panel isin the extended condition shown in FIG. 6.

FIGS. 6–9 illustrate the displacement of the assembly 33 from the fullyretracted position shown in FIG. 7 to the extended condition of FIG. 6,the condition being dictated by the nature of the entry portal of theaircraft to be serviced. In the orientation illustrated in FIG. 7, theassembly 29 is fully retracted thereby exposing a portion of the slot26. In this orientation, the operator may position the cab floorproximate the door of a commuter aircraft having a door which rotatesabout a horizontal axis. With the aircraft door in an open position thecab floor may be positioned proximate the aircraft. Should the aircraftdoor having any upstanding structure associated therewith, the slot 26is dimensioned to permit the passage there through of such structure.After the boarding bridge has been docked with the aircraft with thesecond panel 80 in the position shown in FIG. 9, a generally planarpanel 90 is positioned over the slot 26 to form a passageway over theslot 26 and the aircraft door. The panel 90 is dimensioned to extendfrom a location within the aircraft to the first panel structure 37. Asshown in FIG. 9, the panel 90 extends from a location several inchesinto the aircraft door 91 to a location proximate the pivoted mountingof the first floor panel 37 to the floor 25.

A second embodiment of the invention is illustrated in FIG. 10. Asillustrated in FIG. 10, a boarding bridge 15A (shown in partial view) isfitted on its outer end with a cab 17A. The cab 17A is a generallyenclosed structure having a pair of opposingly positioned upstandingsidewalls 19A surmounted by a ceiling or roof element 20A which extendsbetween the two sidewalls. The cab further includes a floor element 25A,which is generally planar in configuration. The floor element 25Aextends between the two sidewalls. The cab also defines an entryway fromthe main boarding bridge structure. In the illustrated embodiment, theentryway is fitted with a pair of doors 22A. Opposite from the doors 22Ais an open portal 21A which is designed to interface with the fuselageof the aircraft to be serviced by the boarding bridge. The portal 21A isdefined by a framing structure 23A which extends upwardly from the floor25A in a generally inverted U-shaped configuration. The portal frame 23Amay be fitted with a canopy structure (not shown) which extends from theframe to contact the fuselage of the aircraft. A conventionalaccordion-like canopy is anticipated for this purpose.

The floor 25A is formed of two identifiable sections. The main body ofthe floor, herein designated as floor section 25AA extends generallybetween the two upstanding sidewalls 19A. A forward extending section ofthe floor, designated as floor section 25AB extends forward of animaginary line 32A which interconnects the most forward portion of eachof the two sidewalls 19A. As illustrated, the forward section 25AB is agenerally rectangularly configured planer panel having parallel sideedges 28A and a linearly configured leading edge 30A which is orientedorthogonally to the side edges 28A. The leading edge 30A may be fittedwith a bumper structure 27A as shown in FIG. 1. The leading edge 30A isconfigured to be positionable adjacent the fuselage of an aircraft to beserviced by the cab floor assembly.

The edge 28AA of the forward floor section 25AB in conjunction with theleading edge 32A of the floor section 25A defines a slot or recessopening 26A in the floor 25A. This slot 26A is generally defined by theleading edge 32A of the floor section 25AA, the edge 28AA of the floorsection 25AB, the imaginary line 34AB and the imaginary line 34AA. Inthe illustrated embodiment, this slot 26A is visualized as aquadrilaterally configured void adjacent to the floor structure 25A.

The instant invention provides a multi-segmented assembly 29A which maybe introduced into the aforesaid slot 26A in various configurations toform an embarkation platform from an aircraft positioned adjacent tothat slot 26A. In those instances wherein the cab floor is directed toservice a commuter type aircraft having a door assembly which rotatesabout a horizontal axis the slot 26A is left generally devoid ofstructure thereby permitting the passage therethrough of the door andassociated airstair assembly of a commuter aircraft positioned adjacentto the cab floor 25A. Stated otherwise, the assembly 29A is held in aretracted position until the door of the aircraft has been completelyopened and secured in its open orientation. Depending on the particularhand rail arrangement of the airstair, one or more segments of theassembly 29A may then be displaced into the slot to interface with theaircraft door assembly and form an embarkation platform which receivesand accommodates the particular hand rail arrangement. For example asshown in FIG. 12, the assembly 29A is illustrated configured in anarrangement which provides a centrally positioned walking surface 31Ahaving upstanding barriers or guards positioned on the opposing edgesthereof. Recesses or voids 35A and 37A are defined between the walkingsurface 31A and portal 23A of the cab and the edge 28AA of the floorsurface 25AB respectively. These recesses are dimensioned to receive thehand rail structure which would be mechanically associated with the doorof the aircraft being serviced. As further illustrated, the assembly 29Amay also include a pair of vertically positioned guards or hand rails33A, which may function in a protective sense in the absence of a handrail arrangement being present on the door of the aircraft.

FIG. 14 illustrates the multi-segmented assembly 29A in greater detail.As shown, a frame structure 41A is formed of a number of elongate framemembers 43A which are positioned in spaced, parallel relationship to oneanother. The frame members 43A are interconnected to one another bycross members 45A which are positioned orthogonal to the frame members43A and are spacedly positioned from one another. The frame members 43Aand 45A are connected to one another at their various intersections orjunctures to form a frame structure having an upper surface suited forreceiving a planar panel. The panel, which forms the floor element 25A,is connected to the frame structure to define a walking surface.Positioned along the leading edge 32A of the frame 41A is amulti-segmented assembly 29A. The assembly includes a centrallypositioned first floor panel 31A, a second floor panel 53A which ispositioned intermediate the first floor panel 31A and the edge 28AA ofthe floor section 25AB, and a third floor panel 51A which is positionedon the side of the panel 31A opposite from that occupied by the secondpanel 53A. Each of the panels 31A, 53A, and 51A are adapted for rotationabout the imaginary line or axis 32A shown in FIG. 11. Each panel ispositionable in a retracted orientation as illustrated in FIG. 14 and amultitude of extended orientations as will be discussed later.

FIGS. 14–20 depict the first floor panel 31A as including a generallyplanar upper surface having a quadrilateral, e.g., rectangular,perimeter. This upper surface is formed by a planar panel which issecured to a frame element 65A which is positioned adjacent the panel.The frame element 65A includes an elongate section which extendsgenerally along the complete length of the panel and is positionedsubstantially along the central longitudinal axis of the panel. A pairof support panels 67A is mounted to the elongate section spacedly aboutthe elongate section near the proximal end of that section. The supportsterminate in a pair of spacedly oriented ears 67AA which form a clevisadapted to interconnect the first panel with an axle or axis of rotation(not shown). The first panel 31A may be interconnected to a powereddriving structure 62A adapted for rotating the panel about its axis ofrotation. Various power structures 62A are contemplated, includingelectric and hydraulic powered motors.

The first floor panel may, in some embodiments, include one or more sidepanels. As shown in FIG. 15, the first panel 31A is fitted with a firstside panel 81A which is rotatably secured to the longitudinal edge 85Aof the panel 31A and a second side panel 83A which is rotatably securedto the longitudinal edge 87A of the first floor panel 31A. Each of theseside panels 81A and 83A is adapted for form an upstanding barrier orguard for the edge of the first floor panel 31A. For example in thedepiction of the assembly shown in FIG. 17, the first floor panel isdeployed in an extended orientation. Each of the side panels 81A and 83Aare shown upstanding and forming a boundary or guard for thelongitudinal edges of the first floor platform for limiting access tothe open areas on either of the longitudinal sides of the first floorpanel. In FIG. 18 the side panels are illustrated as positioned againstthe frame elements of the second and third panels. In this latterorientation, the side panels are positioned in an angulated orientationas opposed to being positioned vertically upright.

The second floor panel 53A includes an elongate, preferablyquadrilaterally configured upper surface panel which surmounts anunderlying frame structure. The upper surface panel is generally planarin configuration. Similar to the first floor panel the frame structureincludes an elongate section which extends generally over the length ofthe floor panel and is positioned parallel to the central longitudinalaxis of the floor panel. In contrast to the first floor panel, the framestructure of the second floor panel includes a pair of ears 57A whichare secured to the frame structure proximate the distal end of the framestructure. These ears 57A form a clevis in which an auxiliary frameelement 59A is rotatably secured. As shown the element 59A may be agenerally cylindrical member which is mounted on an axle secured inapertures defined in the ears 57A. Element 59A is dimensioned to have alength substantially identical to that of the frame section 58A of thesecond floor panel. This dimensioning of the member 59A permits themember to function as a hand rail when oriented as shown in FIG. 17.Alternatively, the member 59A may be oriented as shown in FIG. 18whereby the member 59A in association with the frame element 58A forms asubstantially isosceles triangle shaped barrier assembly. The framestructure of the second floor panel also includes a pair of supports 61Awhich are secured thereto proximate the proximal end of the floor panel.Similar to the first floor panel these supports extend to form a pair ofaperture defining ears configured to receive an axle for mounting thesecond floor panel for rotation about the axis 32A. In preferredconstructions, the axis of rotation for all three of the floor panels,i.e., the first, second and third floor panels, is the axis 32A.Alternative constructions may utilize respective axis of rotation whichare not co-linear in orientation. Fundamental to the invention is theprovision of a multiple number of adjacently positioned floor panelswhich are rotatable in a vertical plane whereby the floor panels may beselectively positioned relative to one another to form an embarkationplatform while accommodating for the structure of the airstair,handrails and general structure of the door of the aircraft beingserviced. It follows that while the instantly disclosed embodimentutilizes three floor panels in its construction, the invention is notlimited to embodiments which employ three floor panels. In contrast, theinvention contemplates embodiments utilizing two or more floor panels.

The third floor panel 51A is similar in construction to the second floorpanel 53A in that it includes a planar upper surface which surmounts aframe structure constructed from an elongate section and an auxiliarymember 71A rotatably secured in a clevis formed by ears 73A. Theproximal end of the frame structure is adapted with a pair of supportsmounted on either side of the elongate frame member. These supportsterminate in a pair of ears which define respective apertures forreceiving an axle to define an axis of rotation. The third floor panel,in common with the first and second floor panel, is also fitted with arespective drive structure 64A adapted for drivingly rotating the thirdfloor panel about its axis of rotation.

FIGS. 14–21 illustrate the rotation of the assembly 29A from the fullyretracted position shown in FIG. 14 to a number of alternativeorientations designed to service aircraft door configurations of variouscommercial aircraft. In the orientation illustrated in FIG. 14, theassembly 29A is fully retracted thereby exposing the slot 26A. In thisorientation, the operator may position the cab floor proximate the doorof a commuter aircraft having a door which rotates about a horizontalaxis. With the cab floor positioned proximate the aircraft, the door maybe opened by passing the opening door structure through the slot 26A.When the door has reached its opened condition, the first floor panel31A may be rotated in a counterclockwise direction by activating itsrespective drive structure 62A. FIGS. 16–18 illustrate the various stepsnecessary to position the upper surface of the first floor panel 31A ina generally horizontal orientation. Depending on the particulararrangement of the airstair and hand rails of the commuter aircraft, thesecond and third floor panels may be retained in the orientation shownin FIG. 14 or alternatively they may be extended as shown in FIGS.15–18.

FIG. 17 contemplates a handrail construction being associated with theairstair. The spacing of the first floor panel and the second and thirdfloor panels is such that a hand rail may be received between the firstfloor panel 31A and the second floor panel 53A as well as a hand railbeing received between the first floor panel and the third floor panel.The side panels 81A and 83A are positioned in a generally uprightorientation thereby functioning as kick guards for the embarkationsurface formed by the first floor panel.

The auxiliary members 59A and 71A are positioned to extend outwardlytoward the fuselage of the aircraft to form an auxiliary barrier for theassembly. FIG. 18 illustrates a configuration of the frame structure ofthe second and third floor panels whereby the panels form an isoscelesshaped barrier structure for the embarkation platform. In thisparticular configuration, the side panels 81A and 83A are positioned inan angulated orientation relative to the vertical and are abuttedagainst the upstanding framework formed by the second and third floorplatforms.

FIGS. 19–21 illustrate the full extension of the second and third floorpanels to form a contiguous, co-planar orientation of the upper panelsof the three floor panels. In this configuration, the side panels 81Aand 83A are positioned over atop a portion of the upper surfaces of thesecond and third floor panels respectively. In the configuration of FIG.21, the cab floor assembly is adapted to service conventional aircrafthaving a door assembly which rotates about a vertical axis.

A further embodiment of the invention is illustrated in FIGS. 22–24. Asshown, each of the siderails 49 of the first floor panel may be fittedwith a respective side panel 107. Each side panel 107 is an elongate,rectangularly configured panel having a planar upper surface 109 whichforms a floor surface. The proximal longitudinal edge 113 of each sidepanel 107 is hingedly mounted to a respective side rail 49 to permit itsrotation about a horizontal axis 111. The distal longitudinal edge 115of the side panel is dimensioned to rest atop a ledge formed by theunderlying frame of the floor whereby the plane of the side panel may bepositioned substantially co-planar with the remainder of the cab floorwhere the side panel 107 is in the orientation shown in FIG. 22.

Each of the side panels 107 may be fitted with a hydraulic cylinderarrangement 117. The arrangement 117 is secured to the first panelassembly and is structured to rotate the side panel 107 about itsrespective axis 111. Cylinder arrangement 117 provides a means of poweractuating the movement of the side panels 107. In alternativeconstruction, the panels 107 may be constructed to permit manualrotation about their respective axis of rotation 111.

FIG. 24 illustrates an alternative construction wherein the side panels107 are pivotally secured to the frame of the cab floor as opposed tothe first floor panel assembly. In this construction the side panels areadapted to rotate about axis of rotation 121. FIG. 24 illustrates theside panels being raised into an inclined position. As in the embodimentof FIG. 23, the side panels 107 in FIG. 24 may each be fitted with ahydraulic cylinder driven actuation mechanism 125 which is adapted todrivingly rotate the respective side panel 107 about its axis ofrotation. Alternatively, the panels 107 may be constructed for manualactuation.

In both the illustrated embodiments of FIGS. 22–24, the side panels maybe displaced from a generally horizontal orientation to an inclinedorientation, e.g., as shown in FIGS. 23 and 24. Upon being displaced,each side panel reveals an underlying open slot which is dimensioned toreceive upstanding structure of an aircraft door assembly, e.g., topermit the upward passage of the handrails of the door of acommuter-type aircraft. The side panels may be adjusted in orientationto form an upstanding edge for the first panel assembly.

The present invention has been described in detail with reference tospecific embodiments. The invention may be embodied in other specificforms without departing from its spirit or essential characteristics.The described embodiments are to be consider in all respects only asillustrative and not restrictive. The scope of the invention istherefore indicated by the appended claims rather than by the foregoingdescription. All changes which come within the meaning and range ofequivalency of the claims are to be embraced within their scope.

1. An aircraft engagement assembly comprising: a frame, said framedefining a main floor and a support structure for said main floor, saidmain floor defining an elongate slot therein dimensioned to permit thepassage there through of a vertically rotating door of an aircraftparked adjacent said main floor, said aircraft door being pivoted torotate about a horizontal axis; a first floor panel having a first end,said first floor panel being positioned within said slot and pivotedlysecured at said first end to said main floor for vertical pivotedmovement about said first end and substantially out of said slot,sufficient to permit the passage through said slot of said aircraftdoor, said first floor panel defining a first floor surface; and alength extendible second floor panel, secured to said first floor panel,said second floor panel being arranged for reciprocal displacement awayfrom and toward said first floor panel in a direction perpendicular to agenerally horizontal rotational axis of said first floor panel whereinsaid first floor panel and said second floor panel are rotatable aboutsaid first end into a position to form a passageway into said aircraft.2. The aircraft engagement assembly of claim 1 wherein said second floorpanel defines an edge which forms a portion of a perimeter of said mainfloor.
 3. The aircraft engagement assembly of claim 1 wherein saidsecond floor panel is slidably displaceable relative to said first floorpanel.
 4. The aircraft engagement assembly of claim 3 further comprisinga control console associated with a cab, said first floor panel beingpositioned intermediate said control console and said second floorpanel.
 5. The aircraft engagement assembly of claim 4 further includinga drive structure associated with said first floor panel for drivinglyrotating said first floor panel about said generally horizontal axis. 6.An aircraft engagement assembly comprising: a frame, said frame defininga floor, said floor defining a slot therein dimensioned to permit thepassage there through of a vertically rotatable door of an aircraftparked adjacent to said floor; a first floor panel displaceablypositioned within said slot and rotatably associated with said frame,said first floor panel having a first end and an opposing second end,said first floor panel being arranged for pivoted rotation about agenerally horizontal axis, said generally horizontal axis being orientedcollinearly with said first end, said first floor panel defining a firstfloor surface; and a second floor panel, mechanically connected to saidfirst floor panel for slidable displacement along said first floorpanel, said second floor panel being slidably associated with said firstfloor panel for motion along a direction perpendicular to saidhorizontal axis, said second floor panel defining a second floorsurface.
 7. The aircraft engagement assembly of claim 6 furthercomprising a drive structure for forcibly sliding said second floorpanel along said first floor panel.
 8. The aircraft engagement assemblyof claim 6 wherein said first and second floor panels are disposedwithin an opening defined within said floor.
 9. The aircraft engagementassembly of claim 6 wherein said frame further defines a control areafor housing controls for activating said first and second floor panels.10. The aircraft engagement assembly of claim 9 wherein said controlarea is positioned on a left side of said aircraft engagement assemblyfrom the vantage point of a user exiting the aircraft engagementassembly and entering an aircraft.
 11. The aircraft engagement assemblyof claim 10 wherein said first floor panel is positioned intermediatesaid control area and a leading edge of said aircraft engagementassembly.
 12. An aircraft engagement assembly comprising: a frame, saidframe including a main floor and a support structure, including a cab,said main floor defining an elongate slot therein, said floor beingpivotally associated with said frame and said cab; a first floordisplaceably positioned within said slot and pivotally associated withsaid main floor for rotation about a generally horizontal first axis,said first floor defining a first floor surface; and a second floor,positioned within said slot and displaceably associated with said firstfloor panel, for extension and retraction generally along a direction oftravel perpendicular to said first horizontal axis, said second floordefining a second floor surface.
 13. The aircraft engagement assembly ofclaim 12 wherein said second floor panel is positioned adjacent saidfirst floor panel.
 14. The aircraft engagement assembly of claim 12further comprising structure for displacing said second floor panelslidingly within said first floor panel.
 15. The aircraft assembly ofclaim 12 further including a drive structure for drivingly rotating saidfirst floor panel about said horizontal axis.
 16. An aircraft engagementassembly comprising: a frame; a floor positioned on said frame, saidfloor defining an elongate slot therein; a retractable floor panelpositioned within said elongate slot and mechanically associated withsaid frame, said retractable floor panel being configured for verticalrotation, about a horizontal axis, substantially out of said elongateslot to permit the passage through said slot of a vertically rotatingdoor of an aircraft parked adjacent to said aircraft engagementassembly, said horizontal axis being oriented perpendicular to adirection of travel of said floor panel during a retraction movementthereof.
 17. The aircraft engagement assembly of claim 16 wherein saidretractable floor panel is also extendable.
 18. The aircraft engagementassembly of claim 16 further comprising a drive structure for forciblyretracting said floor panel.
 19. The aircraft engagement assembly ofclaim 16 further comprising a drive structure for forcibly rotating saidfloor panel about said horizontal axis.